A jet fighter pilot knows he is able to withstand an acceleration of 9g before blacking out.

Question:

A jet fighter pilot knows he is able to withstand an acceleration of 9g before blacking out. The pilot points his plane vertically down while traveling at Mach 3 speed and intends to pull up in a circular maneuver before crashing into the ground.
(a) Where does the maximum acceleration occur in the maneuver?
(b) What is the minimum radius the pilot can take?